What Time of Day is it Warmest?

What’s the most likely time of day for the daily maximum temperature?

Actually, it depends on a lot of things, including how clouds build up over the course of the day. But would you be likely to guess midnight?

In Fairbanks, Alaska at this time of year the likeliest time of day for the temperature to reach its warmest (or coldest) is midnight. Why?

There are a lot of temperature cycles. The seasonal cycle is obvious — warm in summer, cold in winter. Likewise the diurnal cycle: warmest when the sun is heating the ground; coldest when it is not. There is also an irregular cycle of several days or more, when large-scale winds blow first from the north and then from the south, bringing cold or warm air.

A figure from my thesis, showing how the hour-by-hour temperature (middle line) changed over the time period from Nov 24 through Dec 1.

In mid-Alaska in winter, the daily cycle is very weak. If you take the average temperature for a particular hour of the day, there is a slight warming a little after solar noon, but it is only a degree or two. A single day between about December 1 and January 12 rarely has a discernible temperature rise in the daytime. I actually checked this back when I was preparing my M.S. thesis on ice fog, and determined that during this time period the temperature changes were controlled almost entirely by thermal radiation, with sudden warming when clouds or warm air aloft came in and abrupt cooling when the sky cleared or cold air arrived. Not too surprising, as the sun this time of year is never more than 3 ½ ° above the horizon.

That leaves the seasonal cycle, which is slow, and the irregular variations due to clouds and warm or cold air advection, which can be very large – 100°F over a period of 3 to 4 days, in the extreme. Daily maximum and minimum temperatures are primarily controlled by these longer variations rather than by the very slight solar heating around midday.

Suppose it is warming up, as was happening around November 30 in the graph. The daily minimum for November 30 was at midnight at the beginning of the day. The daily maximum was also at midnight, but at the end of the day. This maximum was also the minimum for the next day, December 1. The opposite would be true if there were a cooling trend. It all happens because maximum and minimum daily temperatures are defined for a 24-hour period from midnight to midnight.

In most places this affects only the minimum, which tends to be just before dawn. In wintertime Fairbanks the effect is enough to completely decouple the daily maximum and minimum temperatures from the solar cycle.

Jarn’s Journal Day 614

Day 614

They seem to have decided I am a benign god, at least. The fear that I felt yesterday gradually subsided today, though the awe remained.

I teleported to the spot I’d been teleporting Songbird from. She was watching for me, though she’d been gathering foodstuffs while she waited, and proudly escorted me to the camp. This time I was shielded against emotions – not entirely, for safety’s sake, but enough I could function.

They were preparing a feast. Every person in the group filed before me while I was enthroned on a large rock,, and each bore a gift. Some were very welcome indeed, like the clothing – far finer than what Songbird had made me, and beautifully decorated with bits of fur, feather and shell. Some were containers, or items of food. Some were decorations, for the head, throat, arms and legs. Others …. Well, I am still not sure what they are, but I smiled and accepted them as the honors they were intended to be.

The food was primitive relative to some I have eaten, but by far the best I since I was stranded here. Songbird is a better cook than I am, but for the first time I realized that her mother had only started to teach her how to prepare food. Not that I found everything they ate to my taste, but I did manage to eat at least a little of everything they offered.

By that time it was growing dark away from the fire, which seemed to grow brighter as the stars appeared. I was wondering how to excuse myself when several of the men of the group came into the firelight, so ornamented with feathers, animal skins tanned with the hair on, and beads that I could not recognize any of those I had met. They moved in patterns – dancing, the shaman called it – while others made sounds by pounding on shoulder blades, blowing on reeds, and doing other things I could not quite see, as well as singing.

Makers of beauty, I thought. Such are rare among my people. What have I found here?

Why an Index?

With 550 posts as of today, I’ve started to have problems remembering what I’ve already put on here. This is particularly a problem with posting existing content such as poems, short pieces from the Summer Arts Festival, or science explanations originally written for the Alaska Science Forum. I can’t remember which books or DVDs I’ve posted reviews on. It also is starting to be a problem when I want to link to a previous post and can’t remember when it was put up or what the title was. And there are posts on this blog that have permanent information, like the series on planet building and the one on horse color genetics, or the book and DVD reviews. I want to make it easier for my readers as well as myself to find things.

I made a start some time ago by adding an index page, which can be accessed from the menu at the top of any page. Right now, the only links are to index pages on my author site. This takes you out of the site and sometimes back in, which is rather clumsy. The index list is also incomplete.

I’m going to start posting an occasional entry which is strictly an index of past posts on a particular topic. These posts will be linked from the index page, and will link forward to the individual blog posts. As it takes a while to find all the posts that belong together, this will be a slow process—probably extending over the next few months. The first in this series, on DVD reviews, is already queued for January 3. Others will follow, most on Thursdays.

I probably won’t be indexing every post. Some, like those early posts which were simply glossary entries for my books, are on the author site and really belong there. Others, like the regular Monday updates on North Pole weather starting in November 2010, can be found easily enough just by using the calendar on the site. But I hope that by the time I have finished this, older posts of interest will be easier to find.

McCaffrey Quote Contexts

All of this week’s quotes but the last are from books by Anne McCaffrey.

“One had to know the rules before one could break them.” Pegasus in Flight. Something Tirla learned early from one of her mother’s men.

“We can’t do something right without doing something wrong” Pegasus in Flight. Rhyssa to Peter, shortly after he has demonstrated his ability to land a shuttle full of aid workers in impossible weather.

“There’s been no major forward progress in all of human history that has not been accompanied by some problems.” Pegasus in Flight. Rhyssa speaking to Peter, trying to comfort him for inadvertently creating a problem.

“Bureaucracy in its usual obstructive role.” Pegasus in Space. Rhyssa and Dorotea discussing Admiral Coetzer’s problems with the Space Authority.

“I was told that there were no old, bold pilots.” Pegasus in Space. Peter when their on-board computers do not agree on whether they are go for a moon voyage. The usual form, often heard here in Alaska, is “There are old pilots and there are bold pilots, but there are no old, bold pilots.”

“The people who do the work are the last ones to know.” Pegasus in Space. Peter and Johnny, after finding that their telekinetic abilities are explained by quantum mechanics, and saying that this should be one of Murphy’s laws.

“It was hard to trust the judgment of the three youngsters.” Sue Ann Bowling, Homecoming. Derik is beginning to suspect Roi is having more problems in school than he is willing to admit, but getting Roi and his two friends to tell him what’s wrong is a problem.

The Future is Wild (DVD review)

Back in 1981 a book came out – After Man, by Dugal Dixon – that I loved to read in the Geophysical Institute Library. It took as a premise that human beings were extinct, and asked what animals might have evolved to fifty million years in the future. The Discovery Channel, with Dougal Dixon, updated the idea and produced a TV series, now available as a set of 3 DVDs, called The Future is Wild. (It’s also available as a paperback book, but this review is of the DVD set.)

Most of the computer-aided nature videos I’ve reviewed to this point have involved re-creations of extinct animals, from early arthropods to mammoths. With these, we generally have enough fossil evidence to have a pretty good idea of how the animal (or plant) was built. Colors, scales, feather or fur are to some extent guesswork – but increasingly evidence is being found even for these. The movement of these extinct animals is increasingly well understood, in part from animators and paleontologists working together.

What will happen in the future takes a lot more guesswork.

These videos cover three time periods: 5 million years in the future, 100 million years from now, and 200 million years ahead, the last assumed to be 100 million years after a catastrophe has produced a major extinction event.

Some things we can do a reasonable job of predicting. We have a pretty good feel for how the tectonic plates move, and just as we can take that back in time to know what the overall distribution of continents and oceans was in the distant past, we can carry it forward to tell where land, water and mountains will be in the future.

Climate is to some extent determined by the distribution of land and water, so future climates can also be very roughly estimated. One factor not so easy to predict, the amount of greenhouse gasses in the air, is uncertain and remains so.

Further, we have a pretty good idea of how evolution works. The best part of the DVD is the tracing back of the evolution of assumed future creatures using our knowledge of how creatures alive today have evolved.

The actual predicted animals are flights of fancy, constrained by known facts about the adaptations of modern plants and animals. The 5 million year scenario assumes an ice age. The shagrats, for instance, correctly show the reduction of appendages, thick coats and increased size typical of cold-evolved animals. But animals that migrate seasonally must have efficient locomotion, as well. Modern animals able to tolerate and thrive in cold climates include some long-legged types such as caribou and moose, for long-distance travel (caribou) and travel through deep snow (moose) as well as compact creatures such as musk oxen. Granted some of the rather poor locomotion of the shagrats may be attributed to the animation (the original program was produced in 2002) but it still seems to me that features leading to poor locomotion would be selected against.

The other two time periods addressed are 100 thousand and 200 thousand years in the future. In the first, carbon dioxide and oxygen levels are assumed to be very high, leading to a hothouse world with insects much larger than today’s. In the second, after a major extinction event, the continents have all come together to create a supercontinent and a global ocean. Fish are assumed to have evolved into a flying creature, though they are spoken of as extinct even though sharks have survived. Inconsistent. The environments are reasonable; I’m not so sure about the inhabitants.

I also have some doubts about the assumed extinctions. It is certainly true that bears, big cats and wolves are under threat today – but the threat is primarily from human activities. The starting point for this assumed evolution, especially in the 5 million year scenario, is critically dependent on how and when humans become extinct, but this is never addressed. Still less is the extinction of entire large clades, such as the mammals. This has rarely happened in the past. Even the dinosaurs are still with us, as birds. Mammals may well evolve into something quite different, but it seems unlikely to me that the strategy of high investment in young and feeding them through special glands will become extinct.

The DVD is worth watching for its insights on how evolution works and some of the more interesting and bizarre relationships it has produced today, as well as the geography and weather patterns of the future. But don’t take the future life-forms too seriously.

Fairbanks Weather 12/26/11

It’s the last Monday of the year, and the first after the solstice. The days are getting longer! Today was almost a minute and a half longer than yesterday. The sun will rise at 10:59 this morning and set at 2:44 this afternoon for 3 hrs 45 minutes of theoretical sunlight, and the sun will reach 2.1° above the horizon. The coldest part of the year is still before us, but at least we’re getting some light back. By this time next week, the days will be more than four hours long.

This morning about noon. Photo to right was yesterday.

We’ve had some snow over the last week, and the snowstake has finally come unstuck. It has some snow frozen on the near side which makes it difficult to read, but I think from the base of the triangle of stuck snow it read about 13” depth when it got too dark to see last night. We had snow (as well as fog) Christmas day, but only about a tenth of an inch was expected. From the way it was snowing around 6 pm, I suspect we got more than that. (8:30 am: we had more than a tenth of an inch, but it’s still too dark to tell how much more. Roads were very slippery and visibility terrible last night. 11:30: Left photo suggests we had about an inch last night.) Temperatures? Below zero even at the warmest, and around 20 to 30 below at night. We don’t really have much warming in daytime, though.

I think I see the first, faint beginnings of buds on the Christmas cactus, after only a little over two weeks of a twelve on-twelve off light cycle. And there is no question about the sunquat, a citrus hybrid. Hope its blossoms smell better than the worm tea I treated all the plants to yesterday!

Six Sentence Sunday

Since it’s Christmas day, I’m posting a bit from a conversation between two of my characters, both in their teens, at a boarding school. This is from a published work, Homecoming. I’ll get back to Tod’s story next week.  Six Sentence Sunday is officially closed for Christmas, so I’ll post a little more than six sentences.

“You planning to do anything special over the holidays?” Cory asked. “Break’s less than a month away, you know.”

“Just stay here, I guess. Xazhar’s staying, too.” That frightened Roi a little. Xazhar was bad enough with classes and plasmaball. Xazhar with nothing to do ….

“Well, you’re invited to come home with me. Ander most always comes. Anyway, Mom loves company she can mother.”

“I’d love to come,” Roi whispered to Coryn, so overcome he could hardly manage the sound.

If you’re interested for next week, check out the website.

North Pole Christmas Eve

Well, not the North Pole.

I live in North Pole, Alaska, which is a suburb of Fairbanks. It’s a little colder than Fairbanks (lower-lying) and needless to say, given its name, tends to be busy around Christmas. Especially Santa Claus House, a tourist emporium which also features letters from Santa, and a mini-ice carnival. Local businesses here, as in Fairbanks, often have ice sculptures in front during the winter.

Since it’s Christmas Eve, I thought I’d let you see some pictures taken in both Fairbanks and North Pole during the last few days.

Looking across the Chena River toward Fairbanks

Display at the Fairbanks North Star Borough building.

The light poles in North Pole are candy canes year round.

Santa Claus is a recurring theme. I'm afraid the sky is typical for warm winter weather.

Ice sculpture at the ice park entrance. These will last most of the winter up here.

Rapumzel and her rescuer in front of a local dentist's office.

Jarn’s Journal Day 613

I might as well give up trying not to interfere.

Songbird walks over from the camp every day, generally loaded down with gifts from the clan. She is quite convinced that I am a god, and that I cannot possibly do without her help in finding food (or bringing over what her relatives have provided) and cooking it. From what she said, her people – including the shaman – are just as thoroughly convinced.

And there are at least one leopard, a family of lions, and a pack of hyenas in the area, any of which would find Songbird, alone, a tasty snack.

The first two days I teleported her back to where she could walk back safely, explaining as I did so that it was too dangerous for her to make the walk alone.

She loves being teleported.

Today I walked back to her relatives’ camp with her, thinking that I would explain the dangers and ask her parents to keep her in the camp.

The next thing I knew, I was in the middle of a greeting ceremony, with a number of strangers who were, to put it mildly, terrified of me.

Now I know how to shield against emotions. With animals, it’s automatic – I have to think to feel them. With other R’ilnai it is a matter of politeness. But for almost two years now, the only sentient being I’ve had to shield against was Songbird, and I generally didn’t, because I wanted to know if she was in trouble. To be blunt, it just isn’t automatic any more, and being surrounded by that much fear ….

Well, I managed to excuse myself somehow. I think I babbled something about having to check the food Songbird had left cooking. But the shaman, just before I bolted, urged me to come tomorrow for a proper greeting – and from the texture of her mind, she meant a proper worshiping.

And I think I agreed.

I had better practice my shielding technique.

The El Nino Carol

Another parody carol, to be sung to the tune of “Greensleeves.”

What child is this, who stops the wind
And changes weather globally,
Who paints the boats of fishermen
And drives their prey to the Arctic.

This, this is El Nino who
Brings thunder to the desert shore.
Whose arms hold a child so wild?
Ah, who but my lady ENSO.

He brings wild storms to the western coasts
And batters California,
Sends drought and floods to Africa
And halts the monsoon in India.

This, this is El Nino who
Brings drought to islands across the sea.
Whose arms hold a child so wild?
Ah, who but my lady ENSO.

So tuna sport in Alaskan seas,
And clouds boil high over desert sands,
And crops are battered or blown to dust
As the child feeds on global warming.

This, this is El Nino who
Brings warmth and rain to Alaska.
Whose arms hold a child so wild?
Ah, who but my lady ENSO.

If you’re not familiar with this aspect of meteorology, El Nino refers to the periodic reversal of winds in the equatorial Pacific, associated with changes in the sea surface temperature field. It got its name from the fact that it was first recognized along the west coast of South America where it hits around Christmas time, hence the name, El Nino (the Christ-child.) It was also called “The Painter,” because the mass die-offs of fish when the water warmed produced quantities of hydrogen sulfide, which in turn affected the color of fishermen’s boats. It is now recognized as a part of the ENSO (El-Nino Southern Oscillation) cycle, which has worldwide effects on climate.